Sillaginidae

Taxobox
fossil_range = Eocene - Recent
name = Smelt-whitings

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image_width = 200px
image_caption = A catch of Japanese whiting, "Sillago japonica"
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Perciformes
subordo = Percoidei
superfamilia = Percoidea
familia = Sillaginidae
familia_authority = Richardson, 1846
type_genus = "Sillago"
type_genus_authority = Cuvier, 1817
subdivision_ranks = Genera
subdivision = "Sillaginodes" "Sillaginopsis" "Sillago"

See text for species.The Sillaginidae, commonly known as the smelt-whitings, whitings, sillaginids, sand borers and sand-smelts, are a family of benthic coastal marine fishes in the order Perciformes. The smelt-whitings inhabit a wide region covering much of the Indo-Pacific, from the west coast of Africa east to Japan and south to Australia. The family is comprised of only three genera and thirty one species, of which a number are dubious, with the last major revision of the family in 1992 unable to confirm the validity of a number of species. They are elongate, slightly compressed fish often light brown to silver in colour with a variety of markings and patterns on their upper body. The Sillaginidae are not related to a number of fishes commonly called 'whiting' in the Northern Hemisphere, including the fish originally called whiting, "Merlangius merlangus".

The smelt-whitings are mostly inshore fishes that inhabit sandy, silty and muddy substrates on both low and high energy environments ranging from protected tidal flats and estuaries to surf zones. A few species predominantly live offshore on deep sand shoals and reefs, although the larvae and juvenile phases of most species return to inshore grounds, where they spend the first few years of their lives. Smelt-whitings are benthic carnivores that prey predominantly on polychaetes, a variety of crustaceans, molluscs and to a lesser extent echinoderms and fish, feeding by detecting vibrations emitted by their prey.

The family is highly important to fisheries throughout the Indo-Pacific, with species such as the Northern whiting, Japanese whiting and King George whiting forming the basis of major fisheries throughout their range. Many species are also of major importance to small subsistence fisheries while others are little more than occasional bycatch. Smelt-whitings are caught by a number of methods including trawling, seine nets and cast nets. In Australia and Japan in particular, members of the family are often highly sought by recreational fishermen who also seek the fish for their prized flesh.

Taxonomy

The first species of sillaginid to be scientifically described was "Sillago sihama", by Peter Forsskål in 1775, who initially referred the species to a genus of hardyhead, "Atherina". cite book | last = Hosese | first = D.F. | coauthors = Bray, D.J., Paxton, J.R. and Alen, G.R. | title = Zoological Catalogue of Australia Vol. 35 (2) Fishes | publisher = CSIRO | date = 2007 | location = Sydney | pages = 1126 | isbn =978-0-643-09334-8 ] It was not until 1817 that the type genus "Sillago" was created by Georges Cuvier based on his newly described species "Sillago acuta", which was later found to be a junior synonym of "S. sihama" and subsequently discarded. Cuvier continued to describe species of sillaginid with the publishing of his ichthyological work "Histoire Naturelle des Poissons" with Achille Valenciennes in 1829, also erecting the genus "Sillaginodes" in this work. The species "Cheilodipterus panijus" was named in 1822 by Francis Buchanan-Hamilton and was subsequently reexamined by Theodore Gill in 1861, leading to the creation of the monotypic genus "Sillaginopsis". John Richardson was the first to propose that "Sillago", the only genus of sillaginid then recognised, be assigned to their own taxonomic family, "Sillaginidae" (used interchangeably with 'Sillaginoidae'), at a meeting of the British Association for the Advancement of Science. [cite journal | last = Richardson | first = John | title = Report on the ichthyology of the seas of China and Japan | journal = Report of the British Association for the Advancement of Science | volume = 15 | pages = 187–320 | date = 1846 | accessdate = ] There were, however, many differing opinions on the relationships of the "sillaginoids", leading to the naturalists of the day continually revising the position of the three genera, placing in them in a number of families. The first review of the sillaginid fishes was Gill's 1861 work "Synopsis of the sillaginoids", in which the name "Sillaginidae" was popularized and expanded on to include "Sillaginodes" and "Sillaginopsis", [cite journal | last = Gill | first = Theodore N. | title = Synopsis of the Sillaginoids | journal = Proceedings of the Academy of Natural Sciences of Philadelphia | volume = 13 | pages = 501–505 | date = 1861 | accessdate = ] however the debate on the placement of the family remained controversial.

In the years after Gill's paper was published, over thirty 'new' species of sillaginid were reported and scientifically described, many of which were synonyms of previously described species, with similarity between species as well as minor geographical variation confounding taxonomists. cite book | last = McKay | first = R.J. | coauthors = | title = FAO Species Catalogue: Vol. 14. Sillaginid Fishes Of The World | publisher = Food and Agricultural Organisation | date = 1992 | url = ftp://ftp.fao.org/docrep/fao/009/t0538e/t0538e06.pdf | location = Rome | pages = 19-20 | isbn = 92-5-103123-1 ] It wasn't until 1985 when Roland McKay of the Queensland Museum published a comprehensive review of the family that these relationships were formally resolved, although a number of species are still listed as doubtful, with McKay unable to locate the holotypes. Along with the review of previously described species, McKay described an additional seven species, a number of which he described as subspecies.cite journal |last=McKay |first=R.J. |year=1985 |title=A Revision of the Fishes of the Family Sillaginidae |journal=Memoirs of the Queensland Museum |volume=22 |issue=1 |pages=1–73 |doi=] After this 1985 paper, additional specimens came to light, proving that all the subspecies he had identified were individual species. In 1992 McKay published a synopsis of the Sillaginidae for the FAO, in which he elevated these subspecies to full species status.

The name "Sillaginidae" was derived from Cuvier's "Sillago", which itself takes its name from a locality in Australia, [FishBase genus | genus = Sillago | year = 2007 | month = September] possibly Sillago reef off the coast of Queensland. [cite web | last = Great Barrier Reef Marine Park Authority | title = Whitsunday Plan of Management Area | publisher = Australian Government | date = 2006-01-09 | url = http://www.gbrmpa.gov.au/__data/assets/pdf_file/0005/1688/pipi_map_whit.pdf | format = pdf | accessdate = 2007-09-01 ] The term "Sillago" is derived from the Greek term "syllego", which means "to meet".FishBase family | family = Sillaginidae | year = 2007 | month = September]

Classification

The following is a comprehensive list of the 31 known extant species of sillaginids, with a number of the species still in doubt due to the loss of the holotype specimen. This classification follows Fishbase, which itself is based on McKay's last revision of the family.

*Family SILLAGINIDAE
**Genus "Sillaginodes"
*** King George whiting, "Sillaginodes punctatus" (Cuvier, 1829).
**Genus "Sillaginopsis"
*** Gangetic whiting, "Sillaginopsis panijus" (Hamilton, 1822).
**Genus "Sillago"
*** Oriental trumpeter whiting, "Sillago aeolus" (Jordan & Evermann, 1902)
*** Golden lined whiting, "Sillago analis" (Whitley, 1943)
*** Shortnose whiting, "Sillago arabica" (McKay & McCarthy, 1989)
*** Silver-banded whiting, "Sillago argentifasciata" (Martin & Montalban, 1935)
*** Asian whiting, "Sillago asiatica" (McKay, 1982)
*** Slender whiting, "Sillago attenuata" (McKay, 1985)
*** Southern school whiting, "Sillago bassensis" (Cuvier, 1829)
*** Boutan's whiting", Sillago boutani" (Pellegrin, 1905)
*** Western trumpeter whiting, "Sillago burrus" (Richardson, 1842)
*** Club-foot whiting, "Sillago chondropus" (Bleeker, 1849)
*** Sand whiting, "Sillago ciliata" (Cuvier, 1829)
*** Eastern school whiting, "Sillago flindersi" (McKay, 1985)
*** Indian whiting, "Sillago indica" (McKay, Dutt & Sujatha, 1985)
*** Bay whiting, "Sillago ingenuua" (McKay, 1985)
*** Thai whiting, "Sillago intermedius" (Wongratana, 1977)
*** Japanese whiting, "Sillago japonica" (Temminck & Schlegel, 1843)
*** Mud whiting, "Sillago lutea" (McKay, 1985)
*** Large-scale whiting, "Sillago macrolepis" (Bleeker, 1859)
*** Trumpeter whiting, "Sillago maculata" (Quoy and Gaimard, 1824)
*** Large-headed whiting, "Sillago megacephalus" (Lin, 1933)
*** Small-eyed whiting, "Sillago microps" (McKay, 1985)
*** Rough whiting", Sillago nierstraszi" (Hardenberg, 1941)
*** Small-scale whiting, " Sillago parvisquamis" (Gill, 1861)
*** Stout whiting, "Sillago robusta" (Stead, 1908)
*** Yellowfin whiting, "Sillago schomburgkii" (Peters, 1864)
*** Northern whiting, "Sillago sihama" (Forsskål, 1775)
*** Soringa whiting, "Sillago soringa" (Dutt and Sujatha, 1982)
*** Estuarine whiting, "Sillago vincenti" (McKay, 1980)
*** Western school whiting, "Sillago vittata" (McKay, 1985)

Evolution

A number of sillaginids have been identified from the fossil record, with the lower Eocene marking the first appearance of the family. The family is thought to have evolved in the Tethys Sea of central Australia, before colonizing southern Australia during the upper Eocene after a seaway broke through south of Tasmania. During the Oligocene, the family spread to the north and south, occupying a much more extensive range than their current Indo-Pacific distribution. Fossils suggest the sillaginids ranged as far north as Poland and Germany, and as far south as New Zealand,cite journal | last = Schwarzhans | first = Werner W | title = Die Tertiare Teleosteer-Fauna Neuseelands, rekonstruiert anhand von Otolithen | journal = Berliner Geowissenschaftliche Abhandlungen Reihe A Geologie und Palaeontologie | volume = 26 | pages = 1–211 | date = 1980 | id = ISSN 0172-8784 | accessdate = ] found in shallow water sedimentary deposits along with other species of extant genera.cite journal | last = Smigielska | first = T. | title = Fish otoliths from the Korytnica Clays (Middle Miocene; Holy Cross Mountains, central Poland) | journal = Acta Geologica Polonica | volume = 29 | issue = 3 | pages = 295–337 | date = 1979 | id = ISSN 0001-5709 | accessdate = ]

There have been at least eight fossil sillaginid species found, all of which are believed to be of the genus "Sillago" based on the only remains found; otoliths. Only one species of extant sillaginid, "Sillago maculata", has been found in the fossil record, and this was in very recent Pleistocene sediments.cite journal | last = Grenfell | first = Hugh R. | coauthors = Werner W. Schwarzhans | title = The fish otolith fauna of the Te Piki Member | journal = Proceedings of the Taupaki Malacological Society | volume = 2 | pages = 12–14 | date = 1999 | doi = | id = ISSN 1174-2348 | accessdate = ]
*"Sillago campbellensis" (Schwarzhans, 1985) Australia, Miocenecite journal | last = Schwarzhans | first = werner W. | title = Tertiare Otolithen aus South Australia und Victoria (Australien) | journal = Palaeo Ichthyologica | volume = 3 | pages = 1–60 | date = 1985 | doi = | id = ISSN 0724-6331 | accessdate = ]
*"Sillago hassovicus" (Koken, 1891) Poland, Middle Miocene
*"Sillago maculata" (Quoy and Gaimard, 1824) New Zealand, Middle Pleistocene
*"Sillago mckayi" (Schwarzhans, 1985) Australia, Oligocene
*"Sillago pliocaenica" (Stinton, 1952) Australia, Pliocene [cite journal | last = Stinton | first = F.C. | title = Fish otoliths from the tertiary strata of Victoria, Australia | journal = Proceedings of the Royal Society of Victoria | volume = 70 | issue = 1 | pages = 81–93 | date = 1958 | accessdate = ]
*"Sillago recta" (Schwarzhans, 1980) New Zealand, Upper Miocene
*"Sillago schwarzhansi" (Steurbaut, 1984) France, Lower Miocene cite journal | last = Steurbaut | first = E. | title = Les otolithes de Teleosteens de l'oligo-miocene d'Aquitaine (sud ouest de la France) | journal = Palaeontographica Abteilung A Palaeozoologie-Stratigraphie | volume = 186 | issue = 1-6 | pages = 1–162 | date = 1984 | id = ISSN 0375-0442 | accessdate = ]
*"Sillago ventriosus" (Steurbaut, 1984) France, Upper Oligocene

Phylogeny

clade| style=font-size:100%;line-height:100%
label1=Sillaginidae
1=clade
label1= "Sillago"
1=clade
1="Sillago"
2="Parasillago"
3="Sillaginopodys"
2= "Sillaginodes"
3= "Sillaginopsis"
Phylogeny of the Sillaginidae, illustrating the three subgenra of "Sillago" proposed by McKay.

The relationships of the Sillaginidae are poorly known, with very similar morphological characteristics and a lack of genetic studies restricting the ability to perform cladistic analyses on the family. Being the fossil sillaginids are based on the comparison of fossil otoliths, with no other type of remains found thus far, this also prevents the reconstruction of the evolution of the family through fossil species. While the position of the Sillaginidae in the order Perciformes is firmly established due to a number of synapomorphies shared with other members of the order, no sister group has been established for the family.cite book|title=Fishes of the World|last=Nelson|first=Joseph S.|publisher=John Wiley & Sons, Inc|year=2006|pages=278–280|isbn=0-471-25031-7] The current taxonomic status of the family is thought to represent a basic picture of the group's phylogeny, with McKay further dividing the genus "Sillago" into three subgenera based on shared morphological characters of the swimbladder. The genera "Sillaginodes" and "Sillaginopsis" have the most plesiomorphic characteristics; being monotypic, and distinct from "Sillago". "Sillago" is further divided into three subgenera based primarily on swim bladder morphology; "Sillago", "Parasillago" and "Sillaginopodys", which also represent evolutionary relationships. Whilst genetic studies have not been done on the family, they have been used to establish the relationship of what were thought to be various subspecies of school whiting, "S. bassensis" and "S. flindersi". Dixon, P.I., R.H. Crozier, M. Black and A. Church. (1987) "Stock identification and discrimination of commercially important whitings in Australian waters using genetic criteria (FIRTA 83/16)". Centre for Marine Science, University of New South Wales. 69 p. Appendices 1-10. ] Furthermore, morphological data suggests a number of Australian species diverged very recently during the last glacial maximum, which caused land bridges to isolate populations of fish. The two aforementioned species of school whiting, "S. maculata" and "S. burrus", and "S. ciliata" and "S. analis" are all thought to be products of such a process, although only the school whiting have anything other than similar morphology as evidence of this process.

Morphology

The Sillaginidae are medium sized fishes which grow to an average of around 20 cm and around 100 g, cite book | last = Kuiter | first = R.H. | coauthors = | title = Coastal fishes of south-eastern Australia | publisher = University of Hawaii Press | date = 1993 | location = U.S.A | pages = | isbn =1 86333 067 4 ] although the largest member of the family, the King George whiting is known to reach 72 cm and 4.8 kg in weight. The body shape and fin placement of the family is quite similar to most of the members of the order Perciformes.cite book | last = Scott | first = T.D. | authorlink = | coauthors = C.J.M. Glover & R.V. Southcott | title = Marine and Freshwater Fishes of South Australia 2nd Edition | publisher = Government Printer | date = 1980 | location = Adelaide ] Their bodies are elongate, slightly compressed, with a head that tapers toward a terminal mouth. The mouth has a band of brush-like teeth with canine teeth present only in the upper jaw of "Sillaginopsis". The cranial sensory system of the family is well developed above and laterally, with the lower jaw having a pair of small pores behind which is a median pit containing a pore on each side. On each side of the elongate head the operculum has a short sharp spine. They have two true dorsal fins; the anterior one supported by 10 to 13 spines while the long rear one is held up by a single leading spine followed by 16 to 27 soft rays. The anal fin is similar to the second dorsal fin, having two small slender spines followed by 14 to 26 soft rays. Their bodies are covered in ctenoid scales, with the exception of the cheek which may have cycloid or ctenoid scales. There is a wide variation in the amount of lateral line scales, ranging from 50 to 141. The swimbladder in the Sillaginidae is either absent, poorly developed, or highly complex with anterior and lateral extensions that project well into the caudal region. A unique duct-like process is present from the ventral surface of the swimbladder to just before the urogenital opening in most species. The presence and morphology of each species' swim bladder is often their major diagnostic feature, with McKay's three proposed subgenera based on swimbladder morphology alone. The sillaginids have only a small range of body colourings and frequently the only colour characteristics to identify between species are the arrangements of spots and bars on their upper bodies. Most of the family are a pale brown - creamy white colour, while a few species are silver all over. The undersides of the fish are usually lighter than the upper side, and the fins range from yellow to transparent, often marked by bars and spots.

Distribution and habitat

, becoming widespread. [cite journal | last = Golani | first = Daniel | title = Impact of Red Sea Fish Migrants through the Suez Canal on the Aquatic Environment of the Eastern Mediterranean | journal = Yale School of Forestry and Environmental Studies Bulletin | volume = 103 | issue = Transformations of Middle Eastern Natural Environments | pages = 375–387 | date = 1998 | url = http://environment.yale.edu/documents/downloads/0-9/103golani.pdf | accessdate = 2007-10-14 ]

Sillaginids are primarily inshore marine fishes inhabiting stretches of coastal waters, although a few species move offshore in their adult stages to deep sand banks or reefs to a maximum known depth of 180 m.cite journal | last = Hyndes | first = G.A. |coauthors=I. C. Potter & S. A. Hesp |year=1996 |month=September |title=Relationships between the movements, growth, age structures, and reproductive biology of the teleosts "Sillago burrus" and "S. vittata" in temperate marine waters |journal= Marine Biology |volume=126 |issue=3 |pages=549–558 |doi=10.1007/BF00354637] All species primarily occupy sandy, silty or muddy substrates, often using seagrass or reef as cover. They commonly inhabit tidal flats, beach zones, broken bottoms and large areas of uniform substrate. Although the family is marine, many species inhabit estuarine environments, with some such as "Sillaginopsis panijus" also found in the upper reaches of the estuary.cite journal |last=Krishnayya |first=C.G. |year=1963 |month= |title=On the use of otoliths in the determination of age and growth of the Gangetic whiting, "Sillago panijus" (Ham.Buch.), with notes on its fishery in Hooghly estuary |journal=indian Joural of Fisheries |volume=10 |issue= |pages=391–412 |doi=] Each species often occupies a specific niche to avoid competition with co-occurring sillaginids, often inhabiting a specific substrate type, depth, or making use of surf zones and estuaries.cite journal | last = Hyndes | first = G.A. |coauthors=M. E. Platell, I. C. Potter |year=1997 |month= |title=Relationships between diet and body size, mouth morphology, habitat and movements of six sillaginid species in coastal waters: implications for resource partitioning |journal=Marine Biology |volume=128 |issue=4 |pages=585–598 |doi=10.1007/s002270050125] The juveniles often show distinct changes in habitat preference as they mature, often moving to deeper waters. No members of the family are known to undergo migratory movements, and have been shown to be relatively weak swimmers, relying on currents to disperse juveniles.

Biology

Diet and feeding

The smelt-whitings are benthic carnivores, with all of the species whose diets have been studied showing similar prey preferences. Studies from the waters of Thailand, Philippines and Australia have shown that polychaetes, a variety of crustaceans, molluscs and to a lesser extent echinoderms and fish are the predominant prey items of the family. [cite journal | last = Tongnunui | first = P. | coauthors = Sano, M. & Kurokura, H. | title = Feeding habits of two sillaginid fishes, Sillago sihama and S-aeolus, at Sikao Bay, Trang Province, Thailand | journal = Mer (Tokyo) | volume = 43 | issue = 1/2 | pages = 9–17 | date = 2005 | url = http://sciencelinks.jp/j-east/article/200601/000020060105A1017511.php | id = ISSN:0503-1540 | accessdate = 2007-10-15 ] [cite journal | last = Mitsuhiro | first = Kato | coauthors = Hiroshi Kohno & Yasuhiko Taki | title = Juveniles of two sillaginids,Sillago aeolus andS. sihama, occurring in a surf zone in the Philippines | journal = Ichthyological Research | volume = 43 | issue = 4 | pages = 1341–8998 | publisher = Springer Japan | date = November 1996 | doi = 10.1007/BF02347640 | accessdate = 2007-10-15 ] cite journal | last = Hyndes | first = G.A. | coauthors = M. E. Platell & I. C. Potter | title = Relationships between diet and body size, mouth morphology, habitat and movements of six sillaginid species in coastal waters: implications for resource partitioning | journal = Marine Biology | volume = 128 | issue = 4 | pages = 585–598 | publisher = Springer Berlin / Heidelberg | date = June 1997 | doi = 10.1007/s002270050125 | accessdate = 2007-10-15 ] Commonly taken crustaceans include carids, decapods, copepods and isopods, while the predominant molluscs taken are various species of bivalves, especially the unprotected siphon filters that protrude from the shells. In all species studied, some form of diet shift occurs as the fishes mature, often associated with a movement to deeper waters and thus to new potential prey. The juveniles often prey on planktonic prey, with small copepods, isopods and other small crustaceans often taken. [cite journal | last = Coull | first = Bruce C. | coauthors = Jack G. Greenwood, Donald R. Fielder & Brent A. Coull | title = Subtropical Australian juvenile fish eat meiofauna: experiments with winter whiting Sillago maculata and observations on other species | journal = Marine Ecology Progress Series | volume = 125 | pages = 13–19 | date = 1995 | doi = 10.3354/meps125013 | id = ISSN 0171-8630 | accessdate = ] Whilst many species have a change in niche to reduce intraspecific competition, there are often many species of sillaginid inhabiting a geographical area. Where this occurs, there is often definite diet differences between species, often associated with a niche specialization. The sillaginid's distinctive body shape and mouth placement is an adaptation to bottom feeding, which is the predominant method of feeding for all whiting species. All larger whiting feed by using their protrusile jaws and tube-like mouths to suck up various types of prey from in, on or above the ocean substrate, as well as using their nose as a 'plough' to dig through the substrate. There is a large body of evidence that shows whiting do not rely on visual cues when feeding, instead using a system based on the vibrations emitted by their prey. Citation | last = Hadwen | first = W.L. | last2 = Russell | first2 = G.L. | last3 = Arthington | first3 = A.H. | title = The food, feeding habits and feeding structures of the whiting species "Sillago sihama" (ForsskaÊ l) and "Sillago analis" Whitley from Townsville, North Queensland, Australia. | journal = Journal of Fish Biology | volume = 26 | pages = 411-427 | url = http://www.blackwell-synergy.com/doi/abs/10.1111/j.1095-8649.1985.tb04281.x | year = 1985 ]

Predators

Smelt-whitings are a major link in the food chain of most systems, and frequently fall prey to a variety of aquatic and aerial predators. Their main aquatic predators are a wide variety of larger fish, including both teleosts and a variety of sharks and rays.FishBase species | genus = Sillaginodes | species = punctatus | year = 2007 | month = Oct ] Marine mammals including seals [cite journal | last = Page | first = Brad | coauthors = Jane McKenzie & Simon D. Goldsworthy | title = Dietary resource partitioning among sympatric New Zealand and Australian fur seals | journal = Marine Ecology Progress Series | volume = 293 | issue = | pages = 283–302 | date = June, 2005 | accessdate = 2007-10-16 | doi = 10.3354/meps293283 ] and dolphins [cite journal | last = Long | first = M. | coauthors = Rob J. Reid | title = Cadmium accumulation and toxicity in the bottlenose dolphin "Tursiops truncatus", the common dolphin "Delphinus delphis", and some dolphin prey species in South Australia | journal = Australian Mammalogy | volume = 20 | issue = 1 | pages = 25–33 | date = 1997 | id = ISSN 0310-0049 | accessdate = 2007-10-17 ] have been reported to have taken sillaginids as a main food source. Seabirds are also another major predator of the family, with diving species such as Cormorants taking older fish in deeper waters while juvenile fish in shallow water fall prey to wading birds. [cite journal | last = Humphries | first = P. | coauthors = Hyndes, G.A & Potter, I.C. | title = Comparisons between the diets of distant taxa (Teleost and Cormorant) in an Australian estuary | journal = Estuaries | volume =15 | issue =3 | pages = 327–334 | date = 1992 | id = ISSN 0160-8347 | accessdate = 2007-10-17 | doi = 10.2307/1352780 ] Sillaginids are often called 'sandborers' due to their habit of burying themselves in the substrate to avoid predators, much in the same way as they forage, by ploughing their nose into the substrate. This defense is even used against human fishermen, who frequently wade barefoot to feel for buried fish. The Sillaginidae are also host to a variety of well studied internal and external parasites, which are represented prominently by the groups Digenea, Monogenea and Myxosporea , Copepoda and Nematoda.cite journal | last = Hayward | first = Craig J. | title = Distribution of external parasites indicates boundaries to dispersal of sillaginid fishes in the Indo-West Pacific | journal = Marine and Freshwater Research | volume = 48 | issue = 5 | pages = 391–400 | publisher = CSIRO | date = 1997 | doi = 10.1071/MF96125 | accessdate = 2007-10-17 ] [cite journal | last = Gibson | first = D.I. | title = Two new lepocreadiids (Digenea) from Sillago spp. (Pisces: Sillaginidae) in Australian waters | journal = Journal of Natural History | volume = 21 | issue = 1 | pages = 159–166 | publisher = Taylor & Francis | date = 1987 | id = ISSN 0022-2933 | accessdate =2007-10-17 | doi = 10.1080/00222938700770041 ]

Reproduction

The Sillaginidae are an oviparous, non guarding family, whose species tend to show similar reproductive patterns to one another. Each species reaches sexual maturity at a slightly different age, with each sex often showing a disparity in time of maturation. [cite journal | last = Coulson | first = Peter G. | coauthors = S. Alex Hesp, Ian C. Potter & Norman G. Hall | title = Comparisons between the biology of two co-occurring species of whiting (Sillaginidae) in a large marine embayment | journal = Environmental Biology of Fishes | volume = 73 | issue = 2 | pages = 125–139 | publisher = Springer Netherlands | date = 2005 | doi = 10.1007/s10641-004-4568-8 | accessdate = 2007-11-08 ] cite journal | last = Hyndes | first = G.A. |coauthors=I. C. Potter & S. A. Hesp |year=1996 |month=September |title=Relationships between the movements, growth, age structures, and reproductive biology of the teleosts "Sillago burrus" and "S. vittata" in temperate marine waters |journal= Marine Biology |volume=126 |issue=3 |pages=549–558 |doi=10.1007/BF00354637] Each species also spawns over a different season and the spawning season often differs within a species, usually as a function of latitude; a feature not unique to sillaginids. [cite journal | last = Sheaves | first = Marcus | title = Is the timing of spawning in sparid fishes a response to sea temperature regimes? | journal = Coral Reefs | volume = 25 | issue = 4 | pages = 655–669 | publisher = Springer Berlin / Heidelberg | date = 2006 | doi = 10.1007/s00338-006-0150-5 | accessdate = 2007-11-08 ] The proximity to shore of spawning is also different between species, as each species usually does not migrate inshore to spawn, even if the juveniles require shallow water for protection, instead relying on currents. [cite journal | last = Jenkins | first = G.P. | authorlink = | coauthors = D.C. Welsford | title = The swimming abilities of recently settled post-larvae of "Sillaginodes punctata" | journal = Journal of Fish Biology | volume = 60 | issue = 4 | pages = 1043–1050 | publisher = Blackwell Synergy | date = 2002 | doi = 10.1111/j.1095-8649.2002.tb02427.x | accessdate = 2007-11-08 ] The fecundity of sillaginids is variable, with a normal range between 50 000 - 100 000. The eggs are small (0.6 to 0.8 mm), spherical and pelagic, hatching around 20 days after fertilisation. [cite book | last = Leis | first = J.M. | coauthors = T. Trnski | title = The Larvae of Indo-Pacific Shorefishes | publisher = New South Wales University Press | date = 1989 | location = Kensington | pages = 372 p | isbn = 978-0824812652] The larvae are quite similar, requiring a trained developmental biologist to identify between species. [cite journal | last = Bruce | first = B.D. | title = Larval development of King George whiting, "Sillaginodes punctata", school whiting, "Sillago bassensis", and yellow fin whiting, "Sillago schomburgkii" (Percoidei: Sillaginidae), from South Australian waters | journal = US National Marine Fisheries Service Fishery Bulletin | volume = 93 | issue = 1 | pages = 27–43 | publisher = Elsevier Science | date = 1995 | doi = | accessdate = ] The larvae and juveniles are at the mercy of the ocean currents, being too weaker swimmers to actively seek out coastlines. Currents are thought to have been responsible for the distribution of mainland species to offshore islands as well as the current widespread distribution of "Sillago sihama". In all studied species, juveniles inhabit shallow waters in protected embayments, estuaries, tidal creeks and lagoons as well as exposed surf zones, usually over tidal flats and seagrass beds. As the fish mature, they generally move to deeper waters, showing a change in diet.

Relationship to humans

The sillaginids are some of the most important commercial fishes in the Indo-Pacific region, with a few species making up the bulk of whiting catches. Their high numbers, coupled with their highly regarded flesh are the reason for this, and their inshore nature also has made them popular targets for recreational fishermen in a number of countries. With overfishing rife in some areas, sustainable aquaculture has allowed the commercial farming of a number of sillaginid species, as well as the use of farmed fish to restock depleted estuaries. At least one species, the Gangetic whiting, has occasionally been used in brackish water aquaria.cite book | last = Schaefer |first = Frank | title = Brackish-water fishes : all about species, care and breeding | location=Rodgau| publisher = Aqualog | date = 2005 | isbn = 3-936027-82-X ]

Commercial fisheries

A small number of sillaginids have large enough populations to allow an entire fishery to be based around them, with King George whiting,cite book | last = Scott | first = T.D. | authorlink = | coauthors = C.J.M. Glover & R.V. Southcott | title = Marine and Freshwater Fishes of South Australia 2nd Edition | publisher = Government Printer | date = 1980 | location = Adelaide ] northern whiting, Japanese whiting, [cite journal | last = Purbayanto | first = Ari | coauthors = Seiji Akiyama, Tadashi Tokai and Takafumi Arimoto | title = Mesh selectivity of a sweeping trammel net for Japanese whiting "Sillago japonica" | journal = Fisheries Science | volume = 66 | issue = 1 | pages = 97–103 | publisher = Blackwell Synergy | date = February 2000 | url = http://www.blackwell-synergy.com/doi/abs/10.1046/j.1444-2906.2000.00014.x?cookieSet=1&journalCode=fis | doi = 10.1046/j.1444-2906.2000.00014.x | id = | accessdate = 2007-01-27 ] sand whiting and school whiting the major species. There have been no reliable estimates of catches for the entire family, as catch statistics generally include only those species taken in large numbers, but there are some species which make up significant numbers of the bycatch. To add to this problem, many of the lesser known species are taken by subsistence fisheries and not reported. From estimates by the FAO, however, it is evident that the family is one of the most important in the Indo-Pacific region, having an estimated catch of 22 718 tonnes in 1990 alone. In this same report, it was shown that the greatest three utilizers of sillaginids were the Philippines, Western Australia and Thailand respectively. The records also suggested that the catch increased from 1983 when it was 17 570 t, up to the last estimate in 1990 of 22 718 t. No such estimates have been carried out since. Modern records for Australia show that this trend has reversed, with all catches from Australia totaling 4 372 t in 2006 compared with 1990's 6000 t haul. [cite book | last = Australian Bureau of Agricultural and Resource Economics | title = Australian Fisheries Statistics 2006 | publisher = ABARE | date = June, 2007 | location = Canberra | pages = 28 | url = http://www.abareconomics.com/publications_html/fisheries/fisheries_07/07_fishstats.pdf | id = ISSN 1037-6879 | isbn = ] Statistics from other countries are unavailable for such comparison.

Sillaginids are taken by a variety of fishing methods, with inshore catches predominantly taken using beach seine nets and cast nets. Due to the alert nature of sillaginids, skill is required on creeping up quietly enough to be able to net fish with a cast net, with experienced fishers often paddling into the sun toward a school and drifting slowly upon it before casting the net. In deeper waters, commercial trawlers and longliners take the most fish, with a number of sillaginids taken in prawn trawls as bycatch. The fish are normally marketed fresh locally under various names, with "Ashuos" commonly used in many countries for various sillaginids. At least one export fishery exists in Australia whereby "S. flindersi" is exported to Thailand where the fish are repackaged and sent to Japan frozen.Citebook | last = Kailola | first = P.J. | coauthors= M.J Williams, R.E. Stewart | title = Australian fisheries resources | location=Canberra| publisher= Bureau of Resource Sciences| year = 1993 | isbn = 0-642-18876-9 ]

Recreational fisheries

In Australia and Japan, members of the family are highly sought after by anglers for their sporting and eating qualities, with anglers often taking more than commercial fishermen in some areas. cite book | last = Wilkinson | first = J. | coauthors = | title = NSW Fishing Industry: Changes and Challenges in the Twenty-First Century | publisher = NSW Parliamentary Library Research Service | date = 2004 | location = Sydney | pages = 174-178 | url = http://www.parliament.nsw.gov.au/prod/parlment/publications.nsf/0/07532F82AC6487FFCA256F16001BBE85 | isbn = 0 7313 1768 8 ] The fishing techniques for all sillaginids are quite similar, with the shallow habitats often requiring light line and quiet movements. Whiting are also popular in part due to their accessibility, with tidal flats around beaches, estuaries and jetties common habitats from where many whiting species are caught without need for a boat. cite book | last = Starling | first = S. | title = The Australian Fishing Book | publisher = Bacragas Pty. Ltd. | date = 1988 | location = Hong Kong | pages = 490 | isbn = 073010141x ] Tidal movements also affect catches, as do lunar phases, causing whiting to 'bite' when the tide is changing. Tackle used is kept light to avoid spooking the fish, and often requires only a simple setup, with a hook and light sinker tied directly to the mainline usually effective. In deeper water fished from boats or where currents are strong, more complex rigs are used, often with hooks tied to dropper loops on the trace. in Australia, some specialist whiting fishermen who target the fish in the surf or on shallow banks use red beads or tubing to attract the fish, claiming the method produces more fish. cite book | last = Horrobin | first = P. | title = Guide to Favourite Australian Fish | publisher = Universal Magazines | date = 1997 | location = Singapore | pages = 102-103 | isbn = ] The bait used is normally anything from the surrounding environment which the whiting naturally prey on, with polychaetes, bivalves, crustaceans such as prawns and crabs, cephalopods and small fish effective for most species. As with most species, live bait is known to produce better catches. Lure fishing for whiting is not normally practiced, but saltwater flies have been used to good effect, as have small soft plastic lures. In some areas, restrictions to the amount and size of fish are in place and enforced by fishery authorities. [cite web | last = Department of Primary Industries | title = Recreational Fishing Guide | work = Limits and Closed Seasons | publisher = Government of Victoria | date = 2007 | url = http://www.dpi.vic.gov.au/dpi/nrenfaq.nsf/LinkView/038067B67D8D0260CA2571F6007C592FB43DB2A1BECEB2A04A256812001DD817#bag | format = pdf | accessdate = 2007-10-10 ]

Aquaculture

A number of sillaginid species have been the subject of brackish water aquaculture in Asia and India, with species including "S. japonica" commonly bred for consumption. In Australia, research has been undertaken in the breeding of sand whiting and King George whiting, and so far only sand whiting shows promise for commercial viability. Citation | last = Burke | first = Michael | title = Marine fingerling production at the Bribie Island Aquaculture Research Centre intensive green-water culture: An historical perspective | url = http://www.aims.gov.au/pages/research/hatchery-feeds/pdf/chapter04.pdf ] King Geroge whiting have been found to take too long to develop to be sustainable, but the use of growth hormones is being investigated. cite book | last = Partridge | first = G. | coauthors = | title = Further development of techniques for the culture of King George whiting for commercial aquaculture or for enhancement of fish stocks in Western Australia - Final Report | publisher = Challenger TAFE | date = 2000 | location = Fremantle | pages = | isbn = ] In Australia, aquaculturally bred sand whiting have also been used to stock depleted estuaries.

References

External links

* [http://www.fishbase.org/Summary/FamilySummary.cfm?ID=307 Fishbase page for Sillaginidae]
* [http://fishpix.kahaku.go.jp/fishimage/search?START=1&JPN_FAMILY=&FAMILY=Sillaginidae&JPN_NAME=&SPECIES=&LOCALITY=&FISH_Y=&FISH_M=&FISH_D=&PERSON=&PHOTO_ID=&JPN_FAMILY_OPT=1&FAMILY_OPT=0&JPN_NAME_OPT=1&SPECIES_OPT=1&LOCALITY_OPT=1&PERSON_OPT=1&PHOTO_ID_OPT=2 Colour photographs of many Sillaginid species ]